Classifications

• • C—CHEMISTRY; METALLURGY
  • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
  • C08J—WORKING-UP; GENERAL PROCESSES OF COMPOUNDING; AFTER-TREATMENT NOT COVERED BY SUBCLASSES C08B, C08C, C08F, C08G or C08H
  • C08J9/00—Working-up of macromolecular substances to porous or cellular articles or materials; After-treatment thereof
  • C08J9/16—Making expandable particles
  • C08J9/18—Making expandable particles by impregnating polymer particles with the blowing agent
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
  • B29C—SHAPING OR JOINING OF PLASTICS; SHAPING OF MATERIAL IN A PLASTIC STATE, NOT OTHERWISE PROVIDED FOR; AFTER-TREATMENT OF THE SHAPED PRODUCTS, e.g. REPAIRING
  • B29C44/00—Shaping by internal pressure generated in the material, e.g. swelling or foaming ; Producing porous or cellular expanded plastics articles
  • B29C44/34—Auxiliary operations
  • B29C44/3442—Mixing, kneading or conveying the foamable material
  • B29C44/3446—Feeding the blowing agent
  • B29C44/3453—Feeding the blowing agent to solid plastic material
• • C—CHEMISTRY; METALLURGY
  • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
  • C08J—WORKING-UP; GENERAL PROCESSES OF COMPOUNDING; AFTER-TREATMENT NOT COVERED BY SUBCLASSES C08B, C08C, C08F, C08G or C08H
  • C08J9/00—Working-up of macromolecular substances to porous or cellular articles or materials; After-treatment thereof
  • C08J9/04—Working-up of macromolecular substances to porous or cellular articles or materials; After-treatment thereof using blowing gases generated by a previously added blowing agent
  • C08J9/12—Working-up of macromolecular substances to porous or cellular articles or materials; After-treatment thereof using blowing gases generated by a previously added blowing agent by a physical blowing agent
  • C08J9/122—Hydrogen, oxygen, CO2, nitrogen or noble gases
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
  • B29K—INDEXING SCHEME ASSOCIATED WITH SUBCLASSES B29B, B29C OR B29D, RELATING TO MOULDING MATERIALS OR TO MATERIALS FOR MOULDS, REINFORCEMENTS, FILLERS OR PREFORMED PARTS, e.g. INSERTS
  • B29K2101/00—Use of unspecified macromolecular compounds as moulding material
  • B29K2101/12—Thermoplastic materials
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
  • B29K—INDEXING SCHEME ASSOCIATED WITH SUBCLASSES B29B, B29C OR B29D, RELATING TO MOULDING MATERIALS OR TO MATERIALS FOR MOULDS, REINFORCEMENTS, FILLERS OR PREFORMED PARTS, e.g. INSERTS
  • B29K2105/00—Condition, form or state of moulded material or of the material to be shaped
  • B29K2105/04—Condition, form or state of moulded material or of the material to be shaped cellular or porous
• • C—CHEMISTRY; METALLURGY
  • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
  • C08J—WORKING-UP; GENERAL PROCESSES OF COMPOUNDING; AFTER-TREATMENT NOT COVERED BY SUBCLASSES C08B, C08C, C08F, C08G or C08H
  • C08J2201/00—Foams characterised by the foaming process
  • C08J2201/02—Foams characterised by the foaming process characterised by mechanical pre- or post-treatments
  • C08J2201/032—Impregnation of a formed object with a gas
• • C—CHEMISTRY; METALLURGY
  • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
  • C08J—WORKING-UP; GENERAL PROCESSES OF COMPOUNDING; AFTER-TREATMENT NOT COVERED BY SUBCLASSES C08B, C08C, C08F, C08G or C08H
  • C08J2203/00—Foams characterized by the expanding agent
  • C08J2203/06—CO2, N2 or noble gases
• • C—CHEMISTRY; METALLURGY
  • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
  • C08J—WORKING-UP; GENERAL PROCESSES OF COMPOUNDING; AFTER-TREATMENT NOT COVERED BY SUBCLASSES C08B, C08C, C08F, C08G or C08H
  • C08J2203/00—Foams characterized by the expanding agent
  • C08J2203/08—Supercritical fluid
• • C—CHEMISTRY; METALLURGY
  • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
  • C08J—WORKING-UP; GENERAL PROCESSES OF COMPOUNDING; AFTER-TREATMENT NOT COVERED BY SUBCLASSES C08B, C08C, C08F, C08G or C08H
  • C08J2203/00—Foams characterized by the expanding agent
  • C08J2203/18—Binary blends of expanding agents
  • C08J2203/182—Binary blends of expanding agents of physical blowing agents, e.g. acetone and butane
• • C—CHEMISTRY; METALLURGY
  • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
  • C08J—WORKING-UP; GENERAL PROCESSES OF COMPOUNDING; AFTER-TREATMENT NOT COVERED BY SUBCLASSES C08B, C08C, C08F, C08G or C08H
  • C08J2207/00—Foams characterised by their intended use
• • C—CHEMISTRY; METALLURGY
  • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
  • C08J—WORKING-UP; GENERAL PROCESSES OF COMPOUNDING; AFTER-TREATMENT NOT COVERED BY SUBCLASSES C08B, C08C, C08F, C08G or C08H
  • C08J2300/00—Characterised by the use of unspecified polymers
  • C08J2300/22—Thermoplastic resins
• • C—CHEMISTRY; METALLURGY
  • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
  • C08J—WORKING-UP; GENERAL PROCESSES OF COMPOUNDING; AFTER-TREATMENT NOT COVERED BY SUBCLASSES C08B, C08C, C08F, C08G or C08H
  • C08J2300/00—Characterised by the use of unspecified polymers
  • C08J2300/26—Elastomers
• • C—CHEMISTRY; METALLURGY
  • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
  • C08J—WORKING-UP; GENERAL PROCESSES OF COMPOUNDING; AFTER-TREATMENT NOT COVERED BY SUBCLASSES C08B, C08C, C08F, C08G or C08H
  • C08J2375/00—Characterised by the use of polyureas or polyurethanes; Derivatives of such polymers
  • C08J2375/04—Polyurethanes
• • C—CHEMISTRY; METALLURGY
  • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
  • C08J—WORKING-UP; GENERAL PROCESSES OF COMPOUNDING; AFTER-TREATMENT NOT COVERED BY SUBCLASSES C08B, C08C, C08F, C08G or C08H
  • C08J2375/00—Characterised by the use of polyureas or polyurethanes; Derivatives of such polymers
  • C08J2375/04—Polyurethanes
  • C08J2375/06—Polyurethanes from polyesters

Definitions

• the present invention relates to an improved and cost efficient method for making expanded (foamed) thermoplastic (eTP) polymers starting from non-expanded thermoplastic polymers (TP).
• eTP expanded thermoplastic
• the invention further relates to a method for forming expanded thermoplastic polyurethane (eTPU) beads or sheets starting from non-expanded thermoplastic polyurethane (TPU) pellets having an average diameter in the range 0.2 mm up to 10 mm or from non-expanded thermoplastic polyurethane (TPU) sheets or parts.
• eTPU expanded thermoplastic polyurethane
• the present invention further relates to eTP/eTPU and moulded products comprising said eTP/eTPU and use of said eTP/eTPU in for example footwear applications.
• Thermoplastic polyurethanes are well-known, in particular, for their very high tensile and tear strength, high flexibility at low temperatures, extremely good abrasion and scratch resistance. TPU's are also known for their superior dynamic properties, in particular, very high rebound figures, low compression set and hysteresis loss. Expanded TPU (eTPU) not only preserves the excellent performance of its base material (non-expanded TPU) but on top of that also provide good shock- absorbing properties and therefore makes eTPU materials very attractive for use in highly demanding shock-absorbing materials such as the application in a shoe sole (especially in professional sport and running shoes).
• foaming methods To fabricate eTPU, more in particular eTPU beads, several foaming methods are known. Several foaming methods use an autoclave (1) wherein first the non-expanded TPU particles are introduced and put under high pressure using gaseous fluids (5) in order to saturate the TPU particles (3) and then there is a depressurizing step to expand the TPU particles (3) and obtain eTPU particles (7). These methods however use a constant pressure and vary the density by temperature, which makes the outcome in terms of density not very predictable. Examples using this method can be found in CN 1016122772, CN 104987525 and WO 2015052265 and is illustrated in Figure 1A-1C.
• WO 2015/052265 makes use of N 2 either by itself or in combination with C0 2 to expand the thermoplastic polymers (TP).
• the pressure during the saturation step is chosen high enough (> 300 bar and higher) to make e.g. N 2 which has a low solubility in thermoplastic polymers (TP) soluble in the TP (as illustrated by example 1 in WO'265).
• eTP expanded thermoplastic polymers
• eTPU expanded thermoplastic polyurethane
• eTP expanded thermoplastic polymers
• a method for producing expanded thermoplastic polymeric (eTP) material and reducing the density of the eTP during the process of producing said eTP comprising at least following steps:
• thermoplastic polymeric (TP) material Providing non-expanded thermoplastic polymeric (TP) material
• the non-expanded TP material is in the form of pellets, sheets or any other shape.
• the TP material is selected from polystyrene (PS), Ethylene Vinyl Acetate (EVA), Poly Vinyl Chloride (PVC) Polymethylmetacrylate (PMMA), Acrylonitrilebutadiene styrene (ABS), thermoplastic polyurethane (TPU).
• the total pressure in the autoclave during the charging step is increased up to a value in the range 100-250 bar by introducing at least one gaseous fluid which is soluble in the TP material and at least one gaseous fluid which has a low solubility or which is insoluble in the TP material.
• the temperature within the autoclave is above the supercritical limits of the gaseous fluids and below the melting temperature of the TP material.
• the gaseous fluid which is soluble in the TP material is selected from C0 2 , H 2 S, acetone, methyl ethyl ketone (MEK), propane, butane and/or pentane, or any combination of these with C0 2 .
• the gaseous fluid which has a low solubility or which is insoluble in the TP material is selected from N 2 , 0 2 , H2, CH 4 , He, Chloro Fluoro Carbons (CFC), Hydro Chloro Fluoro Carbons (HCFC), Hydro Chloro Fluoro Olefins (HCFO), Hydro Fluoro Olefins (HFO), (cyclo)-alkanes such as (cyclo)-pentane and/or noble gases such as krypton, xenon and argon, or any combination of these
• additional gasses having good thermal insulation properties such as Hydro Chloro Fluoro Carbons (HCFC), Chloro Fluoro Carbons (CFC), Hydro Chloro Fluoro Olefins (HCFO), Hydro Fluoro Olefins (HFO), (cyclo)-alkanes such as (cyclo)-pentane and noble gases such as krypton, xenon and argon may be added to the autoclave during the charging step.
• HCFC Hydro Chloro Fluoro Carbons
• CFC Chloro Fluoro Carbons
• HCFO Hydro Chloro Fluoro Olefins
• HFO Hydro Fluoro Olefins
• noble gases such as krypton, xenon and argon
• the gaseous fluids in the autoclave may further comprise additives which are reactive towards the thermoplastic polymer (TP) and which result in modification of the TP during the charging step.
• TP thermoplastic polymer
• the TP material is thermoplastic polyurethane (TPU) and the temperature within the autoclave is within the range 30 - 250 °C.
• TPU thermoplastic polyurethane
• the TP material is TPU in the form of pellets having an average diameter from 0.2 to 10 mm, in particular from 0.5 to 5 mm.
• the partial pressure of the soluble gaseous fluid is below 225 bar, preferably below 200 bar, more preferably below 150 bar
• the total pressure in the autoclave is in the range 50-250 bar, preferably in the range 100-250 bar, more preferably in the range 100-200 bar
• the temperature within the autoclave is within the range 30 - 250 °C, preferably in the range 150-200 °C.
• the partial pressure of the soluble gaseous fluid is below 100 bar, preferably in the range 75-100 bar, more preferably in the range 80-100 bar
• the total pressure in the autoclave is in the range 50-250 bar, preferably in the range 100-250 bar, more preferably in the range 100-200 bar
• the temperature within the autoclave is within the range 30 - 250 °C, preferably in the range 150-200 °C.
• the decrease in pressure during the expansion step is performed at a rate of several bars/second.
• the step of allowing the TP material to reach a saturation state is performed at controlled pressure and temperature within the autoclave until blowing agent saturated TP material is achieved.
• the expanded TP material obtained according to the invention may be used in vibration absorptive materials, packaging materials, automotive interiors, sporting goods, footwear and heat insulating materials and furniture and appliances.
• pellet refers to a non-expanded piece of material (e.g. spherical, ellipsoidal, polyhedral or cylindrical) having an average diameter in the range 0.2 mm up to 10 mm, preferably in the range 0.5 up to 5 mm.
• bead refers to an expanded or foamed pellet having dimensions being 1.2 up to 100 times the size of the original pellet.
• sheet refers to a non-expanded piece of material, with one dimension significantly smaller than the other two, typically but not exclusively a rectangular cuboid and wherein the smallest dimension falls in the range between 0.2 mm and to 100 mm.
• a further example could be a thin pre- shaped part like a shoe sole, or a thin polymer coating layer on a non expandable part.
• expanded sheet refers to an expanded or foamed sheet having dimensions being 1.2 up to 100 times the size of the original sheet.
• Polyurethane refers to the state where the required amount of blowing agent(s) has been dissolved into the Thermoplastic Polymer (TP) with only small internal concentration gradients remaining. The required dissolved amount largely depends on the final required density.
• polyurethane is not limited to those polymers which include only urethane or polyurethane linkages. It is well understood by those of ordinary skill in the art of preparing polyurethanes that the polyurethane polymers may also include allophanate, carbodiimide, uretidinedione, and other linkages in addition to urethane linkages.
• thermoplastic refers in its broad sense to designate a material that is reprocessable at an elevated temperature, whereas “thermoset” designates a material that exhibits high temperature stability without such reprocessability at elevated temperatures.
• fluid uptake or “gas uptake” as used herein refers to the amount of gaseous fluid (gas) that at a specific pressure and temperature is dissolved in the thermoplastic polymer (TP) and is typically expressed in mg gaseous fluid/g TP (mg gas/g TP).
• TP thermoplastic polymer
• solubility refers to the mass parts of TP required to dissolve 1 mass part of gaseous fluid (gas) under the given conditions of pressure and temperature.
• a fluid (gas) is considered soluble in the thermoplastic polymer when under the given conditions of pressure and temperature, the solubility of the gaseous fluid (gas) in the thermoplastic polymer (TP) is > 10 mg gaseous fluid / g TP or in other words 100 or less mass parts of TP are required to dissolve 1 mass part of the gaseous fluid (gas).
• a fluid (gas) is considered insoluble in the thermoplastic polymer when under the given conditions of pressure and temperature the solubility of the gaseous fluid (gas) in the thermoplastic polymer (TP) is ⁇ 0.0001 mg gaseous fluid / g TP or in other words > 10000 mass parts of TP are required to dissolve 1 mass part of the gaseous fluid (gas).
• a fluid (gas) is considered having a low solubility in the thermoplastic polymer when under the given conditions of pressure and temperature the solubility of the gaseous fluid (gas) in the thermoplastic polymer (TP) is in the range > 0.0001 mg gaseous fluid / g TP up to ⁇ 10 mg gaseous fluid / g TP or in other words > 100 up to 10000 mass parts of TP are required to dissolve 1 mass part of the gaseous fluid (gas).
• a process for producing expanded thermoplastic polymeric (eTP) material and tuning the density of the eTP, said method comprising at least following steps:
• the partial pressure of the at least one soluble gaseous fluid is 10 up to 90 % of the total pressure and the density of the eTP material is decreased by increasing the partial pressure of the soluble gaseous fluid and/or by increasing the total pressure in the autoclave during the charging step.
• the at least one gaseous fluid which has a low solubility in the non-expanded TP has a solubility in the non-expanded TP in the range 0.0001 mg gaseous fluid / g TP up to 10 mg gaseous fluid / g TP.
• the at least one gaseous fluid which is soluble in the non- expanded TP has a solubility of > 10 mg gaseous fluid / g TP.
• the at least one gaseous fluid which is insoluble in the non- expanded TP has a solubility of ⁇ 0.0001 mg gaseous fluid / g TP.
• the partial pressure of the at least one soluble gaseous fluid is preferably 10-60 % of the total pressure, more preferably 20-50 % of the total pressure, most preferably 20-40% of the total pressure in the autoclave.
• the process conditions can be set such that the insoluble fluid (gas) does not dissolve in the TP but only helps to create the right condition to improve and dissolve the soluble fluid (gas) in the TP.
• the process conditions can now predict how much fluid (gas) will be dissolved and since the amount of fluid (gas) dissolved in the TP determines the final density of the part, one can now also predict the final density of the TP after foaming by tuning the partial pressure of the at least one gas which is soluble in the TP material and/or by increasing the total pressure during the charging step.
• the partial pressure of the soluble gaseous fluid in the autoclave is increased up to 225 bar, preferably up to 200 bar, more preferably up to 150 bar
• the total pressure in the autoclave is in the range 50-250 bar, preferably in the range 100-250 bar, more preferably in the range 100-200 bar
• the temperature within the autoclave is within the range 30 - 250 °C, preferably in the range 150-200 °C.
• the partial pressure of the soluble gaseous fluid in the autoclave is increased up to 100 bar, preferably in the range 75-100 bar, more preferably in the range 80-100 bar, the total pressure in the autoclave is in the range 50-250 bar, preferably in the range 100-250 bar, more preferably in the range 100- 200 bar and the temperature within the autoclave is within the range 30 - 250 °C, preferably in the range 150-200 °C.
• the non-expanded TP material can be in any shape. Preferred examples are non-expanded TP materials in the form of pellets. Alternatively the non- expanded TP material is in the form of a sheet.
• the total pressure in the autoclave is increased up to a value in the range 100-250 bar, preferably in the range 100-200 bar by introducing at least one gaseous fluid which is soluble in the TP material and at least one gaseous fluid which has a low solubility or which is insoluble in the TP material.
• the step of increasing the pressure in the autoclave (charging step) and introducing gaseous fluid(s) is performed at a temperature within the autoclave below the melting temperature of the TP material.
• the temperature within the autoclave is preferably in the range 30-250 °C, preferably in the range 50-200 °C.
• the gaseous fluid which is soluble in the TP material is selected from C0 2 .
• the gaseous fluid which is soluble in the TP material is selected from H 2 S, acetone, methyl ethyl ketone (MEK), propane, butane and/or pentane, preferably in combination with C0 2 .
• the gaseous fluid which has a low solubility or which is insoluble in the TP material is selected from N 2 .
• the gaseous fluid which has a low solubility or which is insoluble in the TP material is selected from 0 2 , H 2 , CH 4 , He, Chloro Fluoro Carbons (CFC), Hydro Chloro Fluoro Carbons (HCFC), Hydro Chloro Fluoro Olefins (HCFO), Hydro Fluoro Olefins (HFO), (cyclo)-alkanes such as (cyclo)-pentane and/or noble gases such as krypton, xenon and argon preferably in combination with N 2 .
• CFC Chloro Fluoro Carbons
• HCFC Hydro Chloro Fluoro Carbons
• HCFO Hydro Chloro Fluoro Olefins
• HFO Hydro Fluoro Olefins
• (cyclo)-alkanes such as (cyclo)-pentane and/or noble gases such as krypton, xenon and argon preferably in combination with N 2 .
• gasses having good thermal insulation properties such as Hydro Chloro Fluoro Carbons (HCFC), Chloro Fluoro Carbons (CFC), Hydro Chloro Fluoro Olefins (HCFO), Hydro Fluoro Olefins (HFO), (cyclo)-alkanes such as (cyclo)-pentane and noble gases such as krypton, xenon and argon.
• HCFC Hydro Chloro Fluoro Carbons
• CFC Chloro Fluoro Carbons
• HCFO Hydro Chloro Fluoro Olefins
• HFO Hydro Fluoro Olefins
• noble gases such as krypton, xenon and argon.
• the gaseous fluids in the autoclave may further comprise additives which may be reactive (not limited to covalent bonding) towards the thermoplastic polymer (TP) and which may result in modification of the thermoplastic polymer during the charging step.
• additives would aim to modify bulk properties, including for example colorants, fire retardants, anti-static agents, surfactants, peroxides...
• the thermoplastic polymeric (TP) material may be selected from polystyrene (PS), Ethylene Vinyl Acetate (EVA), Poly Vinyl Chloride (PVC) Polymethylmetacrylate (PMMA), Acrylonitrilebutadiene styrene (ABS), thermoplastic polyurethane (TPU).
• the thermoplastic polymeric material is thermoplastic polyurethane (TPU), preferably but not limited in the form of pellets or sheets which may be fabricated using an extruder.
• TPU thermoplastic polyurethane
• the TPU starting material is first melted to form a TPU polymer melt and subsequently cooled and cut into the desired shape such as but not limited to pellets, sheets, or any other form.
• the TP material is in the form of TP pellets (e.g. TPU pellets) whose preferred average diameter is from 0.2 to 10 mm, in particular from 0.5 to 5 mm.
• TP pellets e.g. TPU pellets
• the decrease in pressure is performed at a rate of several bar/second.
• the step of allowing the thermoplastic polymer material to reach a saturation state is performed at controlled pressure and temperature within the autoclave until blowing agent saturated thermoplastic polymeric material is achieved. This step typically can last from several minutes to several hours.
• thermoplastic polymeric material e.g. beads
• density can be tuned by altering the partial pressure of the gaseous fluid which is soluble in the TP material and/or by increasing the total pressure during the charging step.
• the TP polymer material is TPU polymer material.
• TPU and processes for their production are well known.
• TPUs can be produced via reaction of (a) one or more polyfunctional isocyanates with (b) one or more compounds reactive toward isocyanates having a molecular weight in the range of from 500 to 500000 and, if appropriate, (c) chain extenders having a molecular weight in the range of from 50 to 499, and if appropriate in the presence of (d) catalysts and/or of (e) conventional auxiliaries and/or conventional additives.
• the one or more polyfunctional isocyanates used for forming the TPU suitable for making the eTPU material may be well-known aliphatic, cycloaliphatic, araliphatic, and/or aromatic isocyanates, preferably diisocyanates.
• the one or more polyfunctional isocyanates used for forming the TPU suitable for making the eTPU material (such as eTPU beads and eTPU sheets) used in the process according to the invention may consist essentially of pure 4,4' -diphenylmethane diisocyanate or mixtures of that diisocyanate with one or more other organic polyisocyanates, especially other diphenylmethane diisocyanates, for example the 2,4' -isomer optionally in conjunction with the 2,2' -isomer.
• the polyisocyanate component may also be an MDI variant derived from a polyisocyanate composition containing at least 95% by weight of 4,4' -diphenylmethane diisocyanate.
• MDI variants are well known in the art and, for use in accordance with the invention, particularly include liquid products obtained by introducing carbodiimide groups into said polyisocyanate composition and/or by reacting with one or more polyols.
• Preferred polyfunctional isocyanates are those containing at least 80% by weight of 4,4'- diphenylmethane diisocyanate. More preferably, the 4,4'- diphenylmethane diisocyanate content is at least 90, and most preferably at least 95% by weight.
• the one or more compounds reactive toward isocyanates used for forming the TPU suitable for making the eTPU (such as eTPU beads and eTPU sheets) used in the process according to the invention may have a molecular weight of between 500 and 500000 and may be selected from polyesteramides, polythioethers, polycarbonates, polyacetals, polyolefins, polysiloxanes and, especially, polyesters and polyethers or mixtures thereof.
• the one or more compounds reactive toward isocyanates used for forming the TPU suitable for making the eTPU (such as eTPU beads and eTPU sheets) used in the process according to the invention are preferably diols, such as polyether diols and may include products obtained by the polymerization of a cyclic oxide, for example ethylene oxide, propylene oxide, butylene oxide or tetrahydrofuran in the presence, where necessary, of difunctional initiators.
• Suitable initiator compounds contain 2 active hydrogen atoms and include water, butanediol, ethylene glycol, propylene glycol, diethylene glycol, triethylene glycol, dipropylene glycol, 1,3-propane diol, neopentyl glycol, 1,4-butanediol, 1, 5-pentanediol, 2-methyl-l,3- propanediol, 1,6-pentanediol and the like. Mixtures of initiators and/or cyclic oxides may be used.
• the one or more compounds reactive toward isocyanates used for forming the TPU material suitable for making the eTPU (such as eTPU beads and eTPU sheets) used in the process according to the invention are preferably diols, such as polyester and may include hydroxyl-terminated reaction products of dihydric alcohols such as ethylene glycol, propylene glycol, diethylene glycol, 1,4- butanediol, neopentyl glycol, 2-methyl-l,3- propanediol, 1,6-hexanediol or cyclohexane dimethanol or mixtures of such dihydric alcohols, and dicarboxylic acids or their esterforming derivatives, for example succinic, glutaric and adipic acids or their dimethyl esters, sebacic acid, phthalic anhydride, tetrachlorophthalic anhydride or dimethyl terephthalate or mixtures thereof.
• dihydric alcohols such as ethylene glycol, propylene glyco
• Suitable low molecular weight (generally below 400) difunctional compounds that serve as chain extenders used for forming the TPU suitable for making the eTPU material (such as eTPU beads and eTPU sheets) used in the process according to the invention may include diols, such as aliphatic diols like ethylene glycol, 1,3-propanediol, 2-methyl-l,3- propanediol, 1,4-butanediol, 1,5-pentanediol, 1,6-hexanediol, 1,8-octanediol, 1,9- nonanediol, 1,10-decanediol, 1,12-dodecanediol, 1,2-propanediol, 1,3-butanediol, 2,3- butanediol, 1,3-pentanediol,
• diols such as hexanediol, 1,4-butanediol or ethylene glycol. 1,4-Butanediol is most preferred.
• Di-esters of terephthalic acid with glycols having 2 to 4 carbon atoms e.g. terephthalic acid bis(ethylene glycol) or bis-l,4-butanediol, and hydroxyalkylene ethers of hydroquinone, and polyoxytetramethylene glycols having molecular weights of from 162 to 378, are also suitable.
• the reaction mixture does not contain any low molecular weight triol.
• TPU material suitable for making the eTPU material such as eTPU beads and eTPU sheets
• eTPU materials such as eTPU beads and eTPU sheets
• catalysts include catalysts, surfactants, flame proofing agents, fillers, pigments (to provide different colors), stabilizers and the like.
• Catalysts which enhance the formation of urethane and urea bonds may be used, for example, tin compounds, such as a tin salt of a carboxylic acid, e.g. dibutyltin dilaurate, stannous acetate and stannous octoate; amines, e.g.
• the reactants used for forming the TPU material suitable for making the eTPU material may be applied using the so-called one- shot, solvent born, semi-prepolymer or prepolymer method known in the art by a batch or continuous process known to the person skilled in the art.
• eTP and more in particular eTPU can be widely applied in the fields of vibration-absorptive materials, packaging materials, toys for children, sporting goods, aviation models, heat insulating materials, automotive interior materials and furniture and appliances.
• FIGURES
• Figure 1 illustrates an autoclave set up and process steps to achieve expanded polymer particles according to the invention.
• Figure 2 illustrates the effect of altering the total pressure in the autoclave wherein the partial pressure of C0 2 is kept constant at 30 bar on the density of the achieved eTP material.
• Figure 3 illustrates the effect of altering the partial pressure of CO2 in the autoclave wherein the total pressure is 130 bar on the density of the achieved eTP material.
• FIG 1 illustrates an autoclave set up and process steps to achieve expanded polymer particles according to the invention.
• the process steps to achieve expanded polymer particles according to an embodiment of the invention are summarized below:
• Figure 2 illustrates the effect of altering the total pressure in the autoclave wherein the partial pressure of C0 2 is kept constant at 30 bar on the density of the achieved eTP material.
• the process steps to achieve expanded polymer particles according to example 1 are as follows: Heat-up the pressure- vessel (1) till the required temperature (170-180-185°C). Position 30g Avalon A87P 6001 DP UV (dried) in the centre of the autoclave. Close-off the autoclave.
• the resulting eTPU material (beads) are left to stabilise under ambient temperature- & pressure-conditions prior to the density-measurement.
• final bead-density is also influenced by the temperature used during the pressurisation process.
• the usable temperature-range depends on the composition of the TP, and at all times needs to be lower than the melting temperature of the TP.
• a higher process-temperature contributes to a lower bead-density, up to the point that the TP starts to melt and starts to lose its ability to retain the gas inside during the decrease in pressure (expansion-step).
• Example 2 illustrating effect of altering the partial pressure of CQ2 in the autoclave
• Figure 3 illustrates the effect of altering the partial pressure of CO2 in the autoclave wherein the total pressure is 130 bar on the density of the achieved eTP material.
• the process steps to achieve expanded polymer particles according to example 2 are as follows: Heat-up the pressure- vessel till the required temperature (170- 180- 185°C).

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• 2018
  • 2018-10-31 WO PCT/EP2018/079799 patent/WO2019086506A1/en unknown
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